1. Technical Field
The present disclosure relates to a lens assembly of optical imaging system, and more particularly to a lens assembly of optical imaging system applicable to an electronic device.
2. Related Art
In recent years, with the rise of portable electronic devices with photographing capability, the demand for compact photographing lens assemblies has been increasing. The photo-sensing device of an ordinary photographing camera is commonly selected from a charge-coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS) device. With the advance of manufacturing technology, the miniaturization of pixel size of the photo-sensing device is enabled, and the higher pixel density of compact photographing lens assemblies has been realized in the current consumer market. Therefore, obtaining superior imaging quality by the compact photographing lens assemblies is now the main goal for manufacturers to meet the consumer demand.
In order to reduce manufacturing costs, a two-lens structure is commonly adopted in a conventional compact photographing lens assembly of the portable electronic device. For example, U.S. Pat. No. 8,213,097 discloses a compact imaging lens assembly with two lens elements. However, the two lens elements have limited ability to correct the aberration, so the image quality may not satisfy the demand for high-level photographing.
In order to obtain better image quality as well as the miniaturization of the lens assembly, a three-lens optical system is disclosed. For example, U.S. Pat. No. 8,194,172 discloses a three-lens optical imaging lens assembly, including, in order from an object side to an image side, a first lens element with positive refractive power, a second lens element with negative refractive power and a third lens element with negative refractive power. However, only one plastic lens element with lower Abbe number is disposed in the optical imaging lens assembly, so the optical imaging lens assembly may not favorably correct the chromatism. Thus, the optical imaging lens assembly may not satisfy the strict demand for correcting chromatism.
Hence, there is an urgent need for a lens assembly of optical imaging system applicable to a compact and portable electronic device and featuring superior image quality by correcting chromatism.